It is proposed to set a cylindrical boss in a permanent magnet and fix a shaft to the boss to configure a rotor of an electric motor. The permanent magnet and the boss can be simultaneously assembled during injection molding of the permanent magnet by injection-molding a ferrite resin magnet or the like to form the permanent magnet. Therefore, a reduction in assembly man-hours can be attained. When shapes, lengths, and the like of shafts are different, it is possible to handle the shafts using the permanent magnet molded together with the boss by using one kind of mold. Therefore, there is an effect that improves productivity (see, for example, Patent Literature 1).
To make it possible to prevent an electric current from flowing to the roller bearing provided between the rotating shaft and the motor case and thereby to prevent electrolytic corrosion from occurring in the roller bearing and to obtain a rotating-electric machine that is simple in configuration and easy to assemble, it is proposed to arrange an insulation sleeve in the outer circumference of the roller bearing (see, for example, Patent Literature 2).